The proposed investigations are designed to study the role of hydrolytic enzymes in collagen destruction in connective tissue during inflammation. To obtain direct evidence for the participation of collagenolytic enzymes in this process tissue extracts obtained from human gingival specimens at different degrees of inflammation will be assayed for their enzymatic action on purified collagens of Type I (the principal collagen type of connective tissues) and Type IV (basement membrane collagen). In order to study factors regulating collagenase activity in periodontal disease, gingival extracts will be fractionated chromatographically and the fractions will be assayed for the presence of neutral proteases capable of activating latent collagenase isolated from human leukocytes. The activating enzymes will be further purified and biochemically characterized. Another goal of the investigation is to purify and further characterize a neutral protease from human leukocytes that we recently have found to specifically degrade basement membrane collagen. These studies, we hope, will give information needed to understand the biochemical mechanism of collagen degradation in vivo and thereby help to provide means to control the destructive phases of inflammatory conditions, such as periodontal disease.